The ubiquitin-proteasome pathway is critical for the degradation of short-lived proteins in eukaryotic cells, and inhibition of this pathway could induce apoptosis in human leukaemic Mo7e cells. We analyzed the proteo...The ubiquitin-proteasome pathway is critical for the degradation of short-lived proteins in eukaryotic cells, and inhibition of this pathway could induce apoptosis in human leukaemic Mo7e cells. We analyzed the proteomic response of Mo7e cells by inhibiting the ubiquitin-proteasome pathway with . Among 72 protein spots showing significant changes in expression on 2-D protein gels, 4 of them were strongly increased. They are identified as Rho GDP dissociation inhibitor (GDI) βprotein, profilin 1, adenylate kinase isoenzyme 2, and eIF-5A as determined by peptide mass fingerprinting(PMF) using MALDI-TOF-MS a nd展开更多
P28，a 28kD protein from toad (Bufo bufo gargarizans)oocytes,was identified by using P13^suc1-agarose affinity chromatography.Sequence homology analysis of the full-length cDNA of P28(Gene Bank accession number:AF 314...P28，a 28kD protein from toad (Bufo bufo gargarizans)oocytes,was identified by using P13^suc1-agarose affinity chromatography.Sequence homology analysis of the full-length cDNA of P28(Gene Bank accession number:AF 314091)indicated that it encodes a protein containing 224 amino-acids with about 55% iden-tities and more than 70%positives to encodes a protein containing 224 amino-acids with about 55% iden-tities and more than 70% positives to human, rat or mouse UCH-L1,and contains homological functional domains of UCH family.Anti-p28 monoclonal antibody,on injecting into the oocytes,could inhibit the progesterone-induced resumption of meiotic division in a dose-dependent manner.The recombinant protein P28 showed similar SDS/PAGE behaviors to the native one,and promoted ubiquitin ethyl ester hydrolysis,a classical catalytic reaction for ubiquitin carboxyl terminal hydrolases(UCHs).The results in this paper reveal that a novel protein,p28 ,exists in the toad oocytes,is a UCH Ll homolog,was engaged in the process of progesterone-induced oocyte maturation possibly through an involvement in protein turnover and degradation.展开更多
Accumulation of amyloid-β(Aβ) and its neurotoxicity are regarded as a major factor promoting neu-ronal degeneration in Alzheimer's disease (AD). Upon investigation of Aβtoxicity using DNA microarray, we isolate...Accumulation of amyloid-β(Aβ) and its neurotoxicity are regarded as a major factor promoting neu-ronal degeneration in Alzheimer's disease (AD). Upon investigation of Aβtoxicity using DNA microarray, we isolated ubiquitin conjugating enzyme E2-25K/Hip-2 as a mediator of Aβ toxicity. Here we show that expression of E2-25K/Hip-2 was strongly up-regulated in the cultured cortical neurons exposed to Aβ1-42 in vitro and in vulnerable neurons surrounding senile plaques of the brain derived from AD patients and Tg2576 Alzheimer's mice. Aβ1-42-induced neurotoxicity, accumulation of ubiquitin conjugates, and decrease of the proteasome activity were mediated by ubiquitin ligase activity of E2-25K/Hip-2. Aβ-induced展开更多
基金This work was supported by grants from National Natural Science fOundation of China (No.30070377),and National High Technology Research and Development Program of China (No. 2001AA233041).
文摘The ubiquitin-proteasome pathway is critical for the degradation of short-lived proteins in eukaryotic cells, and inhibition of this pathway could induce apoptosis in human leukaemic Mo7e cells. We analyzed the proteomic response of Mo7e cells by inhibiting the ubiquitin-proteasome pathway with . Among 72 protein spots showing significant changes in expression on 2-D protein gels, 4 of them were strongly increased. They are identified as Rho GDP dissociation inhibitor (GDI) βprotein, profilin 1, adenylate kinase isoenzyme 2, and eIF-5A as determined by peptide mass fingerprinting(PMF) using MALDI-TOF-MS a nd
文摘P28，a 28kD protein from toad (Bufo bufo gargarizans)oocytes,was identified by using P13^suc1-agarose affinity chromatography.Sequence homology analysis of the full-length cDNA of P28(Gene Bank accession number:AF 314091)indicated that it encodes a protein containing 224 amino-acids with about 55% iden-tities and more than 70%positives to encodes a protein containing 224 amino-acids with about 55% iden-tities and more than 70% positives to human, rat or mouse UCH-L1,and contains homological functional domains of UCH family.Anti-p28 monoclonal antibody,on injecting into the oocytes,could inhibit the progesterone-induced resumption of meiotic division in a dose-dependent manner.The recombinant protein P28 showed similar SDS/PAGE behaviors to the native one,and promoted ubiquitin ethyl ester hydrolysis,a classical catalytic reaction for ubiquitin carboxyl terminal hydrolases(UCHs).The results in this paper reveal that a novel protein,p28 ,exists in the toad oocytes,is a UCH Ll homolog,was engaged in the process of progesterone-induced oocyte maturation possibly through an involvement in protein turnover and degradation.
文摘Accumulation of amyloid-β(Aβ) and its neurotoxicity are regarded as a major factor promoting neu-ronal degeneration in Alzheimer's disease (AD). Upon investigation of Aβtoxicity using DNA microarray, we isolated ubiquitin conjugating enzyme E2-25K/Hip-2 as a mediator of Aβ toxicity. Here we show that expression of E2-25K/Hip-2 was strongly up-regulated in the cultured cortical neurons exposed to Aβ1-42 in vitro and in vulnerable neurons surrounding senile plaques of the brain derived from AD patients and Tg2576 Alzheimer's mice. Aβ1-42-induced neurotoxicity, accumulation of ubiquitin conjugates, and decrease of the proteasome activity were mediated by ubiquitin ligase activity of E2-25K/Hip-2. Aβ-induced
